R/C2/Plotting-Histograms-and-Pie-Chart/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:01 | Welcome to the spoken tutorial on Plotting Histograms and Pie Chart. |
| 00:08 | In this tutorial, we will learn how to: |
| 00:12 | Plot histograms |
| 00:15 | Plot pie chart |
| 00:18 | Save plots |
| 00:21 | To understand this tutorial, you should know, |
| 00:25 | Data frames in R |
| 00:28 | Basics of Statistics |
| 00:31 | If not, please locate the relevant tutorials on R on this website. |
| 00:39 | This tutorial is recorded on |
| 00:43 | Ubuntu Linux OS version 16.04 |
| 00:48 | R version 3.4.4 |
| 00:52 | RStudio version 1.1.456 |
| 00:58 | Install R version 3.2.0 or higher. |
| 01:04 | For this tutorial, we will use |
| 01:07 | A data frame moviesData.csv |
| 01:12 | A script file myPlots.R. |
| 01:17 | Please download these files from the Code files link of this tutorial. |
| 01:24 | I have downloaded and moved these files to Plots folder. |
| 01:30 | This folder is located in myProject folder on my Desktop. |
| 01:36 | I have also set this folder as my Working Directory. |
| 01:42 | Let us switch to Rstudio. |
| 01:46 | Open the script myPlots.R in RStudio. |
| 01:52 | Run this script by clicking on Source button. |
| 01:58 | movies data frame opens in the Source window. |
| 02:03 | This data frame has 600 rows and 31 columns. |
| 02:09 | It means this data frame has 600 observations of 31 variables. |
| 02:17 | To know about more this dataframe, please refer to the Additional Material section on this website. |
| 02:25 | In the Source window, scroll from left to right to see the remaining objects of movies data frame. |
| 02:34 | Now we will learn how to plot a histogram of the object named runtime in movies. |
| 02:42 | A histogram is |
| 02:44 | A visual representation of the distribution of a dataset. |
| 02:49 | Used to plot the frequency of score occurrences in a continuous dataset |
| 02:56 | Let us switch to RStudio. |
| 02:59 | Click on the script myPlots.R |
| 03:04 | In the Source window, type hist, within parentheses movies dollar sign runtime. |
| 03:13 | Save the script and run the current line by pressing Run button. |
| 03:20 | The histogram appears in the Plots window. |
| 03:24 | Click on Zoom to maximize this plot. |
| 03:29 | In the histogram there are 9 bins. |
| 03:33 | Height of a bin represents the number of observations lying in that interval. |
| 03:40 | Now, we will learn how to add labels to this histogram. |
| 03:46 | Also, we will change the color of bins in this histogram. |
| 03:51 | For this, we will add more arguments to the hist function. |
| 03:56 | Close the histogram. |
| 03:59 | In the Source window, type the following command. |
| 04:04 | Here, we have used the following arguments: |
| 04:08 | main for adding title to the histogram |
| 04:12 | xlab for adding label to the x axis |
| 04:17 | xlim to set the range of values on x axis |
| 04:23 | col to set the color of bins |
| 04:28 | Run the current line. |
| 04:31 | In the Files and Plots window, click on Zoom to maximize the plot. |
| 04:38 | The labels and the title of histogram have been changed. |
| 04:44 | We can observe that most of the movies have the runtime of around 75 to 125 minutes. |
| 04:53 | Now we will modify the number of breaks in the histogram. |
| 04:58 | We can make the groups finer or coarser by modifying the number of breaks. |
| 05:05 | Close this plot. |
| 05:08 | Let us add breaks argument in hist function and set it to 4. |
| 05:15 | In the Source window, type the following command. |
| 05:20 | Save the script and run the current line. |
| 05:25 | In the Files and Plots window, click on Zoom to maximize the plot. |
| 05:31 | Now, there are five bins in the histogram. |
| 05:35 | Remember we had set breaks to be 4. |
| 05:40 | Close the plot. |
| 05:43 | In the Source window, click on movies. |
| 05:47 | I am scrolling from right to left. |
| 05:52 | Now, we will learn how to create a pie chart from the object genre in the movies data frame. |
| 06:00 | A pie chart is |
| 06:02 | A circular chart. |
| 06:04 | Divided into wedge-like sectors, illustrating proportion. |
| 06:10 | The total value of the pie is always 100 percent. |
| 06:15 | Let us switch to RStudio. |
| 06:18 | First, we will make a table of the number of different genres. |
| 06:24 | For this, we use table function. |
| 06:28 | Click on the script myPlots.R |
| 06:32 | In the Source window, type the following command. |
| 06:36 | Run the last two lines. |
| 06:40 | We can see that there are 65 movies in Action & Adventure and 87 movies in Comedy. |
| 06:49 | Now, we draw a pie chart with genreCount. |
| 06:54 | Click on the script myPlots.R |
| 06:58 | In the Source window, type pie within parentheses genreCount. |
| 07:05 | Run the current line. |
| 07:08 | The pie chart appears in the Plots window. |
| 07:12 | Click on Zoom to maximize this pie chart. |
| 07:17 | We can see that Drama has largest share of movies. |
| 07:23 | Now, we will change the color of border in this pie chart. |
| 07:28 | For this, we will add more arguments to the pie function. |
| 07:33 | Close this plot. |
| 07:36 | In the Source window, type the following command. |
| 07:40 | Save the script and run the current line. |
| 07:45 | The modified pie chart appears in the Plots window. |
| 07:50 | Click on Zoom to maximize the plot. |
| 07:54 | Now, we will learn how to save this pie chart as an image on our computer. |
| 08:01 | Close this plot. |
| 08:03 | I am resizing the Files and Plots window. |
| 08:08 | In the Plots window, click on Export. |
| 08:12 | From the drop-down menu, select Save as Image. |
| 08:17 | A window named Save Plot as Image appears. |
| 08:22 | You can select the format in which you want to save your image. |
| 08:28 | I am saving it in JPEG format. |
| 08:33 | Below the Image format option, you can select the directory where you want to save your image. |
| 08:41 | By default, RStudio will save the image in the directory where the script has been placed. |
| 08:49 | I will save the image in this folder. |
| 08:53 | Below the directory, in the field File name, you can write the name of the image to be saved. |
| 09:03 | I am saving the image with the name pieChart with capital C. |
| 09:09 | In the top right corner of this window, you can modify the dimensions of this image. |
| 09:17 | I am setting the width to 650. |
| 09:21 | Please make sure that Maintain aspect ratio is checked. |
| 09:26 | Below Maintain aspect ratio, click on Update Preview button. |
| 09:32 | The image with larger dimensions is shown. |
| 09:37 | Finally, click on Save. |
| 09:41 | I am resizing the Files and Plots window.
|
| 09:46 | Now, click on the Files tab. |
| 09:50 | The image pieChart.jpeg has been saved in the Plots folder. |
| 09:57 | Click on this image to see the saved pie chart. |
| 10:03 | Let us summarize what we have learnt. |
| 10:07 | In this tutorial, we have learnt how to: |
| 10:12 | Plot histograms |
| 10:15 | Plot pie chart |
| 10:18 | Save plots |
| 10:21 | We now suggest an assignment. |
| 10:25 | Read the file moviesData.csv. Create a histogram of the object named imdb_num_votes in this file. |
| 10:41 | Create a pie chart of the object mpaa_rating. |
| 10:48 | Save both the plots. |
| 10:51 | The video at the following link summarises the Spoken Tutorial project. |
| 10:56 | Please download and watch it. |
| 11:00 | We conduct workshops using Spoken Tutorials and give certificates. |
| 11:06 | Please contact us. |
| 11:09 | Please post your timed queries in this forum. |
| 11:14 | Please post your general queries in this forum. |
| 11:19 | The FOSSEE team coordinates the TBC project. |
| 11:23 | For more details, please visit these sites. |
| 11:27 | The Spoken Tutorial project is funded by NMEICT, MHRD, Govt. of India |
| 11:34 | The script for this tutorial was contributed by Tushar Bajaj (TISS Mumbai). |
| 11:42 | This is Sudhakar Kumar from IIT Bombay signing off. Thanks for watching. |
